Urethral Diverticulum Mimicking Malignancy on FDG PET/CT.

Female urethral diverticulum is an uncommon pathologic entity. An 80-year-old woman who underwent left hemicolectomy for descending colon cancer 2 years ago was referred for FDG PET/CT for restaging. FDG PET/CT showed a hypodense FDG-avid periurethral lesion suspicious for malignancy. The FDG-avid periurethral lesion corresponded to a urethral diverticulum, which was initially detected on a pelvic MRI 1 year ago. This case indicates that urethral diverticulum should be included in the differential diagnosis of FDG-avid urethral or periurethral lesions. Careful correlation with the patient's history and anatomic imaging findings is helpful for the diagnosis.